The versatile England international - who made a goalscoring first start for the national team against Portugal last week - has been a vital component of the improved performances of 2004 that has seen the team win five Premiership games out of seven, with one draw.
"We are delighted that Ledley has made this commitment. He can be an important part of what we hope will be a vibrant and improving team.
"His attitude to both training and playing is a coach's dream and he is performing very well for us."
Acting boss David Pleat has expressed his delight over Ledley King's decision to sign a new contract and extend his stay at the club.